Interpreting Cisco ASA Syslog Denied Traffic

Quick Answer

The correct answer is that an inbound UDP packet from an external source to an internal destination was denied. This is determined by parsing the Cisco ASA syslog message, which explicitly lists the protocol as UDP, the direction as inbound (from a lower-security outside interface to a higher-security inside interface), and the action as “denied” due to the access-group “OUTSIDE_IN” applied to the outside interface. On the Cisco CyberOps Associate 200-201 exam, this type of question tests your ability to read and interpret ASA syslog messages for denied traffic, a core skill for security monitoring and incident response. A common trap is confusing the source and destination IPs or misreading the protocol—remember that the ASA always logs the denied packet’s original direction, so “outside” source and “inside” destination means inbound. Memory tip: “UDP denied, outside tried inside” — focus on the protocol, the word “denied,” and the interface pair to avoid the trap.